Research On Shifting Schedule Of AMT In The Pure Electric Bus

As the problems of energy shortage and environmental pollution cause more and more attention, the electric vehicle has become a hot spot of research and development in today’s automotive industry. AMT(Automated Mechanical Transmission) not only has the characteristics of simple structure, high transmission efficiency and reliability, but also has the characteristics of little cost of production and maintenance. Because of these characteristics, AMT is used as one part of the electric vehicle. In this paper, the pure electric bus with 3-speed AMT was for the study, and the focus on AMT shifting schedule in the pure electric bus was conducted deeply, mainly expanding in the following aspects:Firstly, the vehicle simulation model was established on MATLAB/Simulink platform in the modular modeling way,including traction motor model, AMT system model,drivetrain model, vehicle dynamics model, driver model and so on. Establishment of the vehicle model lay the foundation for the research on AMT shifting schedule in pure electric bus and the hardware-in-the-loop simulation.Secondly, the best dynamic shifting schedule and the traditional economic shifting schedule were formulated. The best dynamic shifting schedule and the traditional economic shifting schedule in double parameters shifting schedule of vehicle speed and throttle were designed, and both shifting schedules were the single performance.Thirdly, the mathematical model optimized was set up for multi-performance and comprehensive shifting schedule. It was optimal concluded the dynamic dominate,economy dominate and comprehensive optimal dynamic and economy shifting schedule by genetic algorithm. The simulation results shew that it was feasible for multi-performance shifting schedule based on the genetic algorithm,and the greater dynamic weighting coefficient of comprehensive evaluation function,the better dynamic performance, and the greater economic performance weighting coefficient, the less energy consumed.The last, the hardware-in-the-loop simulation platform for AMT system was built based on dSPACE MicroAutoBox II. AMT dynamic shifting schedule for the pure electric bus was verified by the platform. It was built that the hardware connecting based on dSPACE MicroAutoBox II, so that AMT can achieve static shift. The best dynamic,dynamic dominate, and comprehensive optimal dynamic and economy shifting schedule had the simulation test. Fixing throttle at 60% and 100%, the acceleration time from 8km/hto 50km/h was the standard to verify the preamble theory on dynamic shifting schedules.